From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Technical analysis of battery cell leakage, performance, and design considerations.
| Identifier | ExFiles\Box 35\4\ scan 173 | |
| Date | 20th January 1926 | |
| Contd. -2- EF05/T20.1.26. leak electrically because of the charging effect of the leak current on the metal surfaces involved. nevertheless it can scarcely be doubted that cells do leak in this manner, because the reduction of the negative surface (considered as the negative element of a cell) by the leak current, is continually counteracted by the oxidising effect of the air, and simultaneously with the tendency to reduce the potential of the negative surface by chemical reduction due to the action of the leak current, there is the tendency for it to rise again by the oxidising action, the circumstances of the case being similar to those obtaining during the exposure of active negative plates above the electrolyte. It is therefore of nearly as much importance for a single cell to have a leakage path of as high a resistance as is practically possible, as it is for two or more cells in series. For a 50 ampere-hour (rated) battery, the weight is estimated to be 90 lbs. This is considerably above our limit for the 20 HP, and not far off our limit for the 40/50, and again, the dimensions would be wrong. The outstanding feature of the cell is that no separators are fitted and we may suppose that its charging and high rate discharge resistance would be less proportionally than our standard cells. Contd. | ||